ACCORDING TO THE PLT, HE & THE PASSENGER FLEW TO TRADING BAY TO DUCK HUNT. HE INTENDED TO LAND ON A GRASSY FLAT WHERE HE HAD PREVIOUSLY LANDED. THERE HAD BEEN HEAVY RAIN IN THE AREA BEFORE HE ARRIVED & ONE TO TWO INCHES OF STANDING WATER WAS ON THE LANDING AREA. DRG THE LANDING, HIS BRAKES WERE NOT EFFECTIVE, SO HE ELECTED TO GO AROUND. HE RPRTD THAT AS THE ACFT WAS LIFTING OFF TO GO AROUND, IT HIT A STUMP, BUT CONTINUED FLYING. HE HAD DIFFICULTY CONTROLLING THE ACFT, SO HE DISCONTINUED THE GO-AROUND & LANDED ON TIDAL FLATS WHERE THE ACFT WAS FURTHER DAMAGED.